I believe that the direct effect of the passage of the Seventeenth Amendment is that it improved representation of the people, because now they were able to directly choose Senators, which made the whole voting process a lot democratic.
I believe it was Benjamin Franklin
The main cause of the collapse was governor William Berkeleys refusal to retaliate.
One reason: Plowing large areas of land
A few more reasons: poor farming practices, farmers would loosen up the soil, and the land was deforested, making it loose the roots that held the soil in place.